Can't find that quote either, Atheist, but I don't think Del Boy was really daft or bad. He had a great sense of loyalty to family, once taking a beating from gangsters rather than give them money he'd promised to Rodney as a deposit on a flat. And he had a sort of street cunning, often, though not always, coming out on top (which Basil Fawlty never did, incidentally).
Agree about people's assessment of human nature depending on what kind of person they are themselves. I remember in the early days some Tory MPs saying food banks wouldn't work. 'Won't just be poor people going, will it? After all if you're getting something for nothing . . . '
Probably a few on here who'd have thought the same thing.